Eternum is honey select or honey select 2 with the studio and around 200 gigs of mods. On steam the version is honeyselect2 libido, but then you have to research where to get all the mods to change it from a piece of shit (very limited and censored) to something decent. If you go the japanese version, you'll still need mods.
It's a sex simulator, but when patched you have access to the studio, and it's my understanding that, that is what's used to pose the games. That is all I know.